Method of manufacturing mineral wool.



7 UNITED STATES PATENT OFFICE.

WILLIAM H. KEMLER AND CHARLES GREENE, PITTSBURG, PENN- SYLVANIA.

METHOD OF MANUFACTURING MINERAL WOOL.

SPECIFICATION forming part of Letters Patent No. 637,126, dated November14, 1899.

App filed Il'une 30, 1897. Serial No, 642,942. (No specimens.)

To all whom it may concern:

Be it known that we, WILLIAM H. KEMLER and CHARLES H. GREENE,ofPittsburg, county of Allegheny, and State of Pennsylvania, have inventeda new and useful Improvement in the Manufacture of Mineral Wool, ofwhich the followingis a full, clear, and exact description.

Our invention relates to the making of mineral wool by subjecting slagto a blast of steam, air, or other fluid; and its object is to provide asimple and inexpensive process whereby such a wool may be obtained whichis substantially free from sulfur.

I-Ieretofore in the manufacture of mineral wool the rock mixture orblast-furnace slag has been melted in a cupola-furnace and has containedsulfur or sulfurous compounds in considerable amounts, this sulfur beingderived from the sulfur in the coke used in such furnaces. When saidwool is employed for covering metal surfaces, it has been found that thesulfur or sulfurous compounds therein combined with the metal andcorroded and injured it.

Our invention does away with this injurious element or compound in thewool; and it consists in passing flame or gases which are substantiallyfree from sulfur over a silicious rock mixture which is free fromsulfur, thereby producing a molten bath of slag which is free fromsulfur, and then blowing this slag into wool in the ordinary manner.

In carrying out our improved process in its preferred form we take asilicious material, such as ordinary Ligonier block, and melt it in areverberatory or other suitable tank or hearth furnace, using sufficientlimestone or other suitable flux to form a liquid bath. This Ligonierblock is a well-known silicious stone containing about twenty per cent.of lime. The mixture may be heated from any suitable source of heat inwhich the solid fuel is kept out of contact'with the mixture, and weprefer to use natural gas, which is substantially free from sulfur,though we have found that producer-gas, which contains sulfur in smallquantities, may be used without giving any substantial amount of sulfurin the wool. An oil-burner or other heating means may be employed withinthe scope of our invention, provided the flame or gases aresubstantially free from sulfur or contain it in such minute quantitiesas to'not materially affect the qual* ity of the product. After the masshas been melted in this manner it is tapped out and blown into Wool inthe ordinary manner, the wool thus produced being substantially freefrom sulfur or deleterious sulfur compounds.

Instead of using a silicious material with alkaline earth or othersuitable fluxes a selffiuxing rock or sand may be used, and we intend tocover the same in our claim, and many other variations may be made inthe materials employed for the bath and the furnace used withoutdeparting from our invention, since We claim- The method ofmanufacturing mineral Wool, consisting in passing a flame or gas,substan tially free from sulfur, over a mixture of silicious materialand a flux, substantially free from sulfur, thereby producing a moltenbath of slag with substantially no sulfur, and then blowing this slaginto wool, substantially as described.

In testimony whereof We have hereunto set our hands.

WILLIAM H. KEMLER. CHARLES H. GREENE.

Witnesses:

F. E. GAITHER, O. BYRNES.

